I only use the strongly typed generated classes in code, mostly for notifying the user.

All localized resources in XAML I use the x:Uid. I guess there are ways of using the strongly typed generated class for binding but I don't see the point, it involves much more work than just using x:Uid

Yes, you can use the generated code behind files for localizing your app. Actually using the code behind classes is the default way how to localize the Windows Phone apps as well, see this guide:
http://wp7wonders.wordpress.com/2010/10/17/localize-a-windows-phone-7-application/
Plus it's also safer because you use strongly typed properties instead of plain strings for gathering your localized strings:
AppResources.AppTitle instead of resourceLoader.GetString("AppTitle")